Telephone system



Feb. 9 1926.

E. HORN TELEPHONE SYSTEM '7, 1923 7 Sheets-Sheet 1 Filed Sept.

NAVA

E. HORN TELEPHONE SYSTEM Feb. 9 1926.

Filed Sept. 7", 1923 7 Sheets-Sheet 2 ESR .H r

SS @i Ezs-Z' Harn Feb. 9,1926. 1,572,860

l E. HORN TELEPHONE SYSTEM Filed Sept. '7, 1923 7 Sheets-Sheet 5 E. HORNTELEPHONE SYSTEM Feb. 9', 1926.

Filed sept. 1925 7 Sheets-Sheet 4 Feb. 9 1926.

E. HORN TELEPHONE SYSTEM Filed Sept. '7, 1923 '7 Sheets-Sheet 5 Feb. 91926.

E. HORN TELEPHONE SYSTEM Filed Sept. '7, 1923 '7 Sheets-Sheet 6 Ilm-.Er-[ns Harn Feb. 9 1926. 1,572,860

E. HORN TELEIHONE SYSTEM Filed Sept. 7, 1923 7 Sheets-Sheet 7 Imran :rr-Erw' Harn Patented Feb. 9, 19,26.

1,572,866 UNITED; STATES i PATENT "orriclafA EENsT HORN, 0E BERLIN,GERMANY, assreNoE 'ro SIEMENS a HALSKE AKTIEN- GESELLSCHAFT, orsIEMENssTADT, NEAR EEELIN, GEEMANY.

TELEPHONE SYSTEM.

Application ined september 7, 1923.' serial No. 661,444.

To all 'whom t may concern Be it known that I, ERNST HoRN, a Ger' mancitizen, and a resident of Kulmstrasse 16, Berlin, Germany, haveinvented certain new and useful Improvements in or Relating to TelephoneSystems, of which the following is a specification.

In the known arrangements for metering calls of Vdifferent Values intelephone sys tems, the switching devices which move on a callingsubscribers meterl an amount corresponding to the value of a call set upare connected up over the numerical switch that determines the directionin which the'call is made, or these switching devices are so controlledby the trains of impulses for operating these numerical switches thatthese devices can operate the meters according to the direction in whichthe call is made. These known arrangements have the disadvantage thatthe devices for moving on the meters in telephone areas with main andsub-exchanges are located both in the large main exchanges and in thesmall subexchanges. ,These devices are relatively complicated,especially when duration recording is to be effected in addition to zonemetering. Thus in the known arrangements all exchanges must be providedwith auxiliary devices for instance special time` switches, etc., inaddition to the actual de vices for moving on the meters.

The object of the present invention is to render possible a better andmore economical arrangement of the devices for moving on the meters,this being achieved by centralizing these switching devices in the mainexchanges, where they are preferably associated with the linesconnecting the main exchanges with the sub-exchanges. s In this case itis preferable to locate the metering devices in front of the firstnumerical switch if the calls originate in the sub-exchanges, and tolocate them beyond the first numerical selection stage if the calls aremade to sub-exchanges.

Sincev the trac zones are determined mainly by the location of thecalling and wanted exchanges quite independently of the connectingroute, it is necessary in the known arrangements for the meter actuatingdevices at the different exchanges to have a construction. andcircuit-arrangement according to the location of these exchanges.

Now another feature of the present invention 1s that the differentswitching members of the meter actuating devices at the main exchangesare all exactly alike without regard to the location of the dierentexchanges in the area, said members being connected with one another byauxiliary means, e. g. distribution strips, corresponding to theexchange with which they are associated. l

This application also discloses various novel auxiliary switch circuitarrangements which are claimed in pending application, SerialNo.661,411.6, tiled September 7 I1923. The drawings show one example ofythe lnvention.

Figs. 1 3, inclusive, when laid out from left to right in the ordernamed, diagrammatically show the necessary circuits for establishing a'connection from a subexchange UA1 to a second sub-exchange UAX by way ofthe ma'in exchange HA.

Fi g.4 shows the 'arrangement used in exi 'l l.. tending connectionsfrom lines in the main selector (LW4) and a subscribers instru-- ment,Tn, are shown of a second sub-exchange UAX connected to the same mainexchang f.

A connection between the subscribers Tn,

and Tn, belonging to the same sub-exchange UAI is set up as follows:

The preselecting devies LVW1 and II.

V VV1 having been positioned, the first numerical switch I GrVV1 of themain exchange is connected up over the trunk line VL,L to y the mainexchange HA. The train of impulses for operating this numerical switchalso causes the auxiliary digit switches MS1 in the sub-exchange UA1 andMS, in the main exchange HA to be operated. The

first group selector is, for instance, set on the third level, whereuponit takes into use a free trunk line4 VL2 to the second group selectorII.GW,.

Simultaneously with the positioning of the second group selector, theauxiliary digit switch MS1 is also moved on by the calling subscriber.If now the number of impulses for setting this switch is such that theconnection remains in the calling sub-exchange (UAI) the auxiliary digitswitch MS, releases the trunk line VL1 to the main exchange HA and thusalso releases the first group selector IGVV, as well as the trunk lineVL2 and the second group selector IIGVVT At the same time the secondpreselector ILVVV1 located in front of the auxiliary digit switch MS1 isstarted up.

This preselector now takes into use a free trunk line VL3 to a localfinal selector LW1,

whereupon thelatter is set on the contact tof.

which the subscribers line to instrument Tn., is connected.

A connection between the subscriber Tn, (UAI) and the subscriber, Tfn.,of the main exchange (HA) extends over the following connecting devicesIVW1 II.VW,`, Ue, VL (MS2) ZSl/ZS2, IGVV1, LIV?, tothe station Tm.

A connection between vthe subscriber Tn, (UAI) and the subscriber Tn,who is connected to the sub-exchange UAX located in the same trafficzone, extends over the followingJ connecting devices and lines: I.VW II.VW U6, VL., (MS2) ZS,/ZS2` I.GVV VL2, II.GW VL, and LW4 to 'station Tm.A connection between the subscriber Tn', of the sub-exchange UAI and asubscriber of an exchange located in the tra-flic zone II extends overthe following connecting devices and lines: I.VW ILVWU Ue, VLl, (MS,),ZS,/ZS2, I.GVV (level 8) VL5. VLS, II.GW2, VL7 to the exchange in zoneII.

A connection between the subscriber Tn3 of the main exchange HA and asubscriberof an exchange-located in the trafiie zone II extends over thefollowing connect-ing devices :I.VW. II.VW,. I.GW2,VL8, ZS,/ZS2', VLQ,VLG, II.GW2, VL7 to the exchange in zone II. i

The apparatus ZS1/ZS2 and ZS1 /ZS2 comprises the switching devices formoving on the meters of the calling subscribers. It can be clearly seenfrom Fig. 8 that all these switching devices are located in the mainexchange-HA, thus those switching devices which are operated foroutgoing calls from a sub-exchange are located in front of the firstnumerical switch in the connection, th at is to say in the present casein front of the first group selector I GW1. Those switchingy devices(ZS,/ZS2), which are operated for calls from the main exchange arehowever located beyond the' first numerical switch, namely between thelatter (LGI/V2) and the second numerical switchjIIGVV.. The secondnumerical switches (II.GW2) are used for all calls, that is to say forthose outgoing from the main exchange subscribers as well as .for thoseoriginated by sub-exchange subscribers. The meter operating VdevicesZS1/ZS2 are so arranged that they are not connected up for callsoutgoing from'a subcxchange subscriber. This is achieved by providingseparate first numerical switches for sub-exchange and main exchangesubscribers and by connecting the meter operating devices ZS,/ZS2 to thelines VLB, VL, which inter-connect the contacts of both selector groupsI.GW2, I.GW,. Hence the trunk lines VL5, VL, from the contacts of thefirst group selectors for sub-exchanges (I.GrW1 lead directto secondgroup selectors II. W2, while the trunk lines VLB, VL, extend from thecontacts of the first group selectors for the main exchange subscribers(I.GW2) over the meter operating devices (ZSJ/ZSJ).

In Figs. 1 Vto 4 are shown the circuits concerned in setting up thedifferent connections. A connection between the subscriber Tfn, of thesub-exchange UAI and the subscriber Tn5 of the sub-exchange UAX willfirst be explained, both these subscribers being in the same trafiiczone. l

When the subscriber Tn, originates a call, the relay R1 of thepreselector LVW1 operates in known manner and causes this preselector toset itself on a free II.VW,. When this has been done, the followingcircuit is established: earth, battery, contact `111, windings I and IIof relay T1, wiper 2,

contacts 3, 4t2, relay R2, earth. The relay T',y in known manner stopsthe preselector, disconnects the calling relay R1 at the contacts 5 and6251 and connects through the speaking leads a, b at thelcontacts 7 and825,. At the second preselector ILVVV, vthe operated relay R2 at contact91'2 closes the circuit of the driving magnet D, and at con-v tact 1072prepares the energizing circuit for the test relay T2. The circuit ofthel driving magnet extends as follows: earth, battery, contacts 9?2,11u, magnet 1) contacts 12d,. 13152, earth. The following circuit isestablished when the second preselector ILVW, finds a free repeater Ueand associated therewith a free trunk line VI1 leading to the mainexchange HA: earth, battery, contact 1012, windings I and II of relayT2, contact 14u, wiper 15, cont-act 16, lead 17, contact 18s, winding Iof relay C contact 1911 earth. The relays T2 and C, operate. The relayT2 at contact 13252 opens the circuit of the driving magnet D1, atcontact 15t2 short circuits its high resistance winding I and switchesthrough the Atesting and blocking lead from the first over itswindingII. Furthermore at contact 23e1 the impulse contact 25a'1 of rclay A, isconnected to the lead 24 of the trunk line V L1. The operated relayAlopens the contact 25H1, over which are given the impulses for settingthe numerical switches, at'

contact 26a.l short circuits the relay V2 while at the same timel byopening contact 27a-1 removing the shortcircuit from the winding II ofrelay C, and also opens the impulse contact 28a1 for themagnet D2 ot theauxiliary digit switch MS,. Among other circuit changes the relay B1opens its contact 29bl, thereby removing the short circuit round thewinding I of relay V1. The latter operates, opens its contacts 19, 30and 337:, and closes its contacts 31 and 3212),. The closure of thecontact 32', causes the rotary magnet D2 of the auxiliary switch MS, tohe connected up: earth, contacts 32s 3402, wiper 35, contact 36, magnetD2, (m8,), battery, earth. The wiper 35-is moved on to the secondContact 37 and therebythe following circuit is closed: earth, contacts321` l, 3402, wiper 35, contact 37, lead 38, winding 39 of the repeater,contact 4052, lead 41 ot the trunk line VLl, contacts 4202, 437W, relayV2, winding I, Contact 44 of the auxiliary switch MS2, wiper 45,resistance 46', battery, earth. The relay V2 operates, opens its Contact46c2 and closes its contacts 471-2, 4303, 49a2 and 5053. Atcontact481,2. the rotary magnet D3 (m32) of the auxiliary digit switch MS2 isconnected to the impulse contact. 51 ot a relay A2, while at the contact491g, the tiret group selector of the main exchange is taken into useover the following circuit: earth, contact 4902, relay C2, resist-- ance52. Contact 53s lead 54, oit normal contact 55k of the first groupselector LGIV, winding I of relay Bw winding I of relay C3, battery,earth. The relays C2 (Fig. 2) as well as B3 and C3 (Fig. 3) operate. Therelay C2 closes the contact 5602 located in parallel with 4902, opensthe contact 4202 and closes the contacts 57 and 5302. At co-ntact 5702the lead 41 is connected with the 6303 prepares a holding circuit overboth its windings I and II, which becomes operative as soon as thecontact 55k 1s opened at the first step of the group selector. The relayB2 at its contacts 64 and 65?):1 connects the rclay A, to the lea-d 66and conne-cts the winding 1I of relay B2 to the lead 59. The impulses ofthc first t-rain transmitted by the calling subscriber, besidesoperating the `first `group selector -LGrlV1 located at the mainexchange, also operate the auxiliary' diga mia-hais, located in front ofthis group selector and the auxiliary digit switch MS1 in thesub-exchange. It will be assumed that for this conne-:tion only asingle-payment has to be made, since the sub-exchange UAX lies in thesame traffic zone as the sub-exchange UAI. If for instance the irsttrain of impulses comprises three impulses. then all the three numericalswitches (LGlVl, MSI, MS2) are moved on three steps. T he inlpulsesaresent in known manner by interrupting the loop at the calling.subscribcrs stat-ion, so that the relays A1 and B,v release at eachimpulse and the relay A, closes its impulse contacts 25a.1 and 2864,.The circuits for operating the differcnt apparat-us extend as follows:

1. for the auxiliary digit switch MS1 in the sub-exchangef earth,contacts 3211 67f, 23052, 36,magnet D2, battery, earth. 2. for theimpulse receiving relays A2 (Fig. 2) and A3 (Fig. 3) in the mainexchange: earth, contacts 25al1 (Fig. 1) 230 lead 24, thence over relayA2, contact 5053, resistance 68, battery, earth, and also thence overcontact 69153, lead 66, contact 641) relay A2, battery, earth.

The relay A2 in known manner brings about the setting of IGVV, on thethird level. The relayv A2 (Fig. 2) closes the circuit for the drivingmagnet D3 (m82) as follows: earth, contact 51a2, winding II of relay V3,Contact 48012, magnet D3 (m32), battery, earth. Hence at the end of thetrain lof impulses the wipers 45 and 62 of the .y

auxiliary digit switch MS2 stand on the contacts 70 and 71 respectively.)Vlien the relay V2 has released, it cannot vbe again energized duringthe further setting up of the connection. noted that as soon as therelay C2 is energized, the relay U2. is also. energized as follows overits winding I: earth, contact 7202, winding I otrelay U2, contact 73M,driving magnet D4 of the counting switch ZS2. battery, earth. The magnetD4 is not energized owing to the high resistance of winding I of relayU2. The relay U2 has therefore opened its contact 74ul and therebyprevents the magnet D(ms2) being connectel up after relay V3 releases.

The transmission of the first impulse from the calling station and theopening of the Contact 260il bv the impulse receiving rclay A1, causesthe removal of the short circuit round the winding I of relay V2. Hencerelay V2 'can operate and it opens its con- It should however here betacts 34212 and 4002 and closes thel Contact 74122. Battery is therebyconnected over 'resistance 7 5 to the lead 41 of the trunk line VL1 andthe relay Bs (Fig. 3,) is thereby maintained energized over its windingII as follows: earth, battery, resistance 75, contact 74112, lead 41,contact 5702, normal contact 76 and wiper 7710i the switch ZS2, junctionpoint 78, contact 7 Qt., lead 59, conlact 651) winding II of relay B2,earth. The relay B2 is also connected to the junction point 78 (Fig. 2).It is, however, of high resistance and is so much vshunted by thewinding II of relay B3 (Fig. 3) that it cannot operate.

The first group selector IGVV1 in known manner hunts for a free trunkline VL2 and the connection is completed by the positioning of the othernumerical switches (e. g. the IIGVV1 and LW4 shown in Fig. 3.)

It is assumed that the final selector LIV, is provided with a sideswitch and that the impulse relays A5 and B5 are disconnected after thetransmission of the trains of impulses for operating the drivingmagnets. It is also assumed that position 13 is the speaking position ofthe side switch, into which it goes after the wanted subscriber Tn, hasanswered and in which position a feeding relay Y for the subscriber Tn5is connected up. In position 13 of the side switch, battery is connectedto the lead 82 over a resistance 80 and the side switch contact 81, sothat the relay B2 in Fig. 2 is energized as follows: earth, battery,resistance 80, side switch contact 81 (position 13), lead 82, contact 83and wiper 84 of the second group selector II.GW2, contact 85122, contact86 and wiper 87 of the first group selector I (ErWl,- contact 88 2, lead59, contact 79t3, junction point 8, relay B2, earth. The relay B2operates and causes the switch ZS2 to move on to the next contact sincethe circuit for the driving magnet D4 (zsII) is closed as follows:earth, interrupter 89, contact 9052, off normal contact 91/czsII of theswitch ZS2, magnet D4 (zsII), battery, earth. Hence the wiper 77 of ZS2is moved to the Contact 92. The magnet D4 cannot be again operated,since the contact 91irz3II has now been opened. The relay B2 furthermoreat its contact 9352 connects earth to the relay A2. In addition therelay S1 is connected over contact 10452 to the lead 54. The relay S1operates, opens its contact 53r-1 and closes its contacts 99s1 and11231.

At the contact 112s1 the relay U2 is maintained energized over itswindin II.

To ret-urn now to the circult changes, which take place in the callingsub-exchange UAI: it has already been described how the irst train ofimpulses, which operated the first group, selector I.GW2, also moved onl the digit switch MS1 for instance to the contact 94. At the end ofthis train of im-l pulses, the relay U1 1s energized as follows: earth,contacts 3211 34?;2, wiper 35, contact 94, relay U2, contacts 119f and1200 battery, earth. The relay U1 connects itself in a holdingr circuitat 1ts contact 121u1; this circuit can, however, only be closed so longas local connecting devices LV1 accessible from the preselector II.VIV1are free, since only in this case is the contact 122g closed. The secondtrain of impulses for setting the second group selector II.GrIV1 causesthe driving magnet D2 (m8,) of' the digit switch MS1 to be operated inthe same manner as did the first train of impulses. Thereby the wiper 35reaches for instance the contact 118. After the release of relay V2 dueto the prolonged short circuit of its winding I at contact 26(11, therelay F is energized: earth, contacts 43211 34122, wiper 35, contact118, windings I and II of relay F, battery, earth. The relay F closesits contact 95 and thereby connects itself in a holding circuitdependent on the contact 96111 ofthe slow releasing relay V2.Furthermore the relay F opens the contact 67]", so that the rotarymagnet D2 (m8,) cannot be operated further by other trains of impulses.

If at the end of the conversation the wanted subscriber is the irst tohang up, the side switch of the final selector IV4 reaches the position14. The circuit for the relay B2 (Fig. 2) is however maintained, sincein this position also the contact 81 (Fig. 3) is closed. lVhen thecalling subscriber TaJL (Fig. 1) also hangs up his receiver, the relayA1 is permanently de-energized, hence the contact 26a1 remains open andthe contact 27a1 remains closed. The winding II of relay C, is shortcircuited, and the relay C1 therefore. releases. Among other circuitchanges, it opens its contacts 22 and 230 and closes its contacts 97 and980,. The circuit of winding I of the slow acting relay V1 is opened atcontact 2201. At contact 97e1 however the followingA circuit is closed:earth, battery, winding II of relay V2, contact 970 lead 24, windingI ofrelay A2, contact 9362, earth, so that the relay V1 remains energized inthis circuit. The relay A2 also operates and gives a metering impulse tothe meter impulse repeating relay ZR at the repeater Ue of the exchangeUAI over the following route: earth, battery, contacts 9981, 100a2,rela-y HR, contact 5702, lead 41, contacts 4002, 980 relay ZR, contact311:1, earth. The relay ZR closes its contact 101er and thereby connectsthe low resistance 102 in parallel with the high resistance 103 to thelead 17 coming from the second preselector ILVIVI. Thereby the currentflowing over the meter Z at the first preselcctor IVIV, is increased tosuch an extent that the meter can operate and the conversation can bemetered. After the relay HR has been energized, the driving magnet D2(28H) of the switch ZS2 is energized as follows: earth, contacts 51a2,105w, magnet D2, (zsII) batter earth. The relay HR at its contact 106 1'short circuits the relay A2, hence it releases. The wiper 77 is moved onone step by the magnet D4 and.

reaches the contact 107. The relay B2 is now short circuited becauseearth is connected to the junction point 78 over the contact 5802, wiper62, the contacts 71 and 107 and the Wiper 77. The relay B2 releases andopens the contacts 98 and 104. The opening of contact 10462 interruptsthe holding circuit over the relays C2, S1 and C2, and the first groupselector LGVV1 as well as the succeeding switches are released in knownmanner. When the contact 9362 is opened, the relay V1 at the repeater Ueis de-energized and releases.

The digit switches MS1 and MS2 as well as the counting switch ZS2 arereleased in the following manner:

After the release of relay V1 the relays V2 and S are energized in thefollowing route: earth, Contact 331) W-inding II of relay V2, off normalcontact 107km?1 o-f the digit switch MS2, winding II of relay S,battery, earth. Both the relays S and V2 operate and close theircontacts 108o2 and 109s. Thereby the following circuit is closed for therotary magnet D2 (mel) earth, contacts 1107) 109s, 108c2, 67 f, 28a2,36, magnet D2, battery, earth. The magnet D2 operates, moves on thedigit switch and at its contact 111012 short circuits the relay V2. Therelay V2 releases and opens its Contact 108, whereby the magnet D2releases and opens the contact 111. The relay V2 now again operates andagain closes the contact 108112. This cycle is repeated until theauxiliary digit switch reaches its normal position, wherein the offnormal contact 1077017181 is opened. After the release of the rotarymagnet D2 it is-impossible for the relay 2 t-o again energize.

The relay vU2 in Fig. 2 was, as already mentioned, maintained energizedduring conversation over a contact 112 of relay S1 and its winding II.Since the relay S,L was cle-energized after the release of relay B2, therelay U2 is also de-energized and closes the following circuit for themagnet D2 (m82) earth, battery, magnet D3, contact 46c/12, ofi' normalcontact 113cms2 of the digit switch MS2, contact 74u2, winding II ofrelay HR, earth. The magnet D3 operates and closes the followingcircuit: earth, battery, winding II of relay U2, contact 1146132,winding III of relay HR, earth. The relay U2 at contact 74u2 opens thecircuit of the magnet D2, whereupon the magnet releases and opens thecircuit of the relay U2. This cycle is repeated until the digit switchreaches its normal position, in which the contact 113kms2 is opened.

The switch ZS2 is moved into its normal posltlon at the same time as thedigit switch MS2, since the circuit of driving ma net D4 (.zsII) isclosed as follows: earth, attery, magnet D2, ofi' normal contact;lllczsII, normal contact 116czsI, contact 117%2, windmg II of relay HR,earth. The magnet D4 also closes a contact 118e@l inthe circuit of WmdinII of rela U2, so that the moving on of t e switch S2 is dependent onlyonv the operation of the magnet D4 and the relay U2. The driving circuitfor the magnet D4 1s finally opened when the switch ZS2 reaches its`normal position since the contact 11510282 is then opened.

Consideration will now be given to the case when a connection is set upwith a subscriber who is connected to an exchange located in a differenttraffic zone. Exchanges for which a zone payment has to be made are, forinstance, reached over the eighth level, of the first numeral switch,Hence the first group selector is set on the eighth level, in which ii;takes into use a free trunk linc VL5. The continuation of the trunk lineVL, is indicated by VLe in Figure 3. At the point (200, 201, 202) where-these two lines meet, a trunk line VL, is connected coming from thebank contacts of those first numerical switches (I.GW2) that areaccessible to subscribers of the main exchange. Between the contacts203, 204, and 205 at the last mentioned first numerical switch I.GW2 andthe meeting points 200,

201 and 202 are located the meter operating devices that vare onlyoperated for calls originated by the main exchange subscribers. Thesemeter operating devices (MS2, Z/Sl' /ZS2) are therefore not employed forthe' present connection. When` the first group selector IGVV1 is set onthe eighth level, the digit switch MS1L is at the same time set on tothe eighth contact, which is for instance the contact 118. After the`relay V2 has released, the relay F is energized as be-l fore andprevents the rotary magnet D2 being operated by further trains ofimpulses.

The wiper 45 of the digit switch MS2 is likewise `set on to the eighthcontact, which in Fig. 2 is designated by`121. The winding III of relayHR is short circuited for thev duration of the impulse train by theContact 47%. The relay is however energized upon the release of therelay V2: eartlnbattery, resistance'46, wiper 45, contact 121, relay HR,winding III, earth. The relay HR operates and byopening the contact 73M'interrupts the circuit over the winding I of relay U2. The relay U2releases and closes the contact 74u2 whereby the following circuit isclosed for the magnet D3.: earth, battery, magnet D2, contacts 46'02,113cms2, 74w2, relay HR, winding II,

earth. The magnet D8 by closing its `contact 114d2, energizes the relayU2 over its winding II in series with the winding III of relay HR. Therelay U2 operates, and

5 opens the contact 74u,2,whereby the clrcuit for the magnet Ds isopened, ,so that it deenergizesy and opens the contact 114d2. Thereuponthe re ay U2 releases and closes contact 74w2. This cycle is repeateduntil 1 the wiper 45 reaches the contact 122. This contact cannot bereached-by the first train of impulses transmitted by the callingsubscriber which will never exceed ten, As soon as the wi er 45 reachesthe contact 122, the followmg circuit is established:

earth, batinry, resistance 46', wi er 45, contact 122, winding I ofrelay 2, lead'60,

contact 123, wiper 62 contact 5802, earth.,

The relay Vs operates, opens the circuit for the automatic rotation ofthe digit switch MS2 by opening the contact 46v2, and at contact 481,'3connects the rotary ma n et D 3 to the impulse contact 512. The digltswitch MS2 has now been brought into a position in which it can beoperated by the second train of impulses. The transmission of the secondtrain of impulses causes the relay A2 to be operated in the manneralready described and the relay at its contact 5'1a2 sets the rotarymagnet D3 in o eration. The

circuit of the rotary magnet 2 contains the f winding II of relay V3, sothat this relay remains energized for the duration of the train ofimpulses. The energi'zation of the relay V2 after the switch 45 has beenset on the contact 122 also causes the relay HR tov release, thuspreventing the rotary magnet D4 of the switch ZS2 being operated by therelay A2.

Let it be assumed that the second train of impulses comprises only asingle impulse and hence the wiper 62 of the digit switch MS2 has beenset on the contact 124, over which isl connected up thereafter wiper 125of the zone switch ZSl.

After the connection has been set up and the wanted subscriber hasanswered in the manner already described, the relay B2 is energized andcauses the switch ZS2 to take one step as before; hence the wiper 77 ofZS2 stands on contact 92. Furthermore the contacts 126 and 127 areclosed in this position of ZS2. The relay S1 has been again operatedover the contact 10452 in the manner alread described and has connectedup the relay 2 over its winding II so that the contact 128102 is openedand the contact 129u2 is closed.

The meter operating device has a time switch associate-d with it, whichis moved on by the magnet D5 at fixed intervals of time. After theContact 129142 has been closed, the time switch is moved out of itsnormal position since the magnet D5 -is energized as follows: earth,interrupter 130,

contacts 13152, 126282, normal contact 132ze, contact 129u2, rotarymagnet D5 (ze), battery, earth. At the first step of the time switch Zethe contact 132ee 1s opened and the contact 133ee is closed.

It is assumed in the present example that the time switch has'36 contactpositions and is moved on by a time contact 134ulc, which is closed ever5 seconds; it ma or'instancc be operated7 b an electric cloc I-lence onerotation of te time switch corresponds to a duration of 3 minutes, whichhas been assumed to be a unit loi. time for the calls. The contact 134is closed shortly before the time switch has com leted a rotation.Thereby the corresponding subscribers are given a buzzer tone, fromwhich they recognize that a 3 minute period will be completed in a fewseconds and that Jrurther charge will be made if the conversation iscontinued. The circuit'for repeating the signal, which is closed uponthe closure of thecontact, extends as follows: earth, secondary windingof theinduction coil 135, contact 136%, wilzr 137, contact 134ee,winding Il 'of relay 2, winding II of relay A2, earth. The buzzer toneis repeated from the windings II of the relays A2 and B2 to the windingsI of these relays and can therefore be heard by the subscribers. Whenthe time switch upon its rotation reaches the last contact (the 36th)the driving magnet De, of the zone switch ZSl is energized as follows:earth, 135, contact 136153, wiper 137, contact 138ze, magnet Da (zal),battery earth. The zone switch ZS1 is moved on one step. The circuitchanges just described are repeated at each rotation of the time switchZe.

The zone switch ZS2, which is controlled by the time switch Ze, has itscontactsconnected with the contacts of the counting switch ZS2. Thewiper 125 of ZS1 is connected up for calls to the second tralic zone.The normal contact 139 is connected with the fourth contact 140 of theswitch ZS2. Since this switch is set on the `iirst contact 92 as alreadymentioned, it has to take three steps before the Wiper 77 reaches thecontact 140. Hence for connections in the traic zone II, three meteringimpulses have to be transmitted for each conversation unit. When thezone switch ZS1 has been advanced one step at the end of the lirst unitof time, the wiper 125 stands on the Contact 141 which is connected withthe seventh contact 142 of ZS2.

For calls to the traiic zone III the wiper 143 is connected up, as hasbeen assumed in Fig. 2. The normal contact 144 upon which this wiper isstanding, is connected to the sixth contact 145 of ZS2. Hence for callsto the third traic zone five impulses are transmitted for each timeunit.

For calls to the fourth traffic zone, for

` switch ZS1 is always moved on one ste which the wiper 146 of ZS1 isconnected up, ,seven metering im ulses have to be .transmitted for eachtime unit, land for calls to the fifth trafiic zone nine metering im)ulses have to be transmitted. l

n the resent system, devices are also provided 4or limiting the durationof the dierent calls according to their value. This is achieved by meansof the switch ZS2. In the present exam le this switch has 32 positions.The last ve `contacts 147 to 148 are multipled tovether and areconnected with a relay l. Since the zon a the end of a three minuteperiod, the wiper 125 of the zone switch ZS1 reaches the ninth contact149 at the expiration of 8 time units in the case of calls to thetraiiic zone II; the contact 149 is connect-ed to the contact 147 oftheswitch ZS2. When the call has lasted so long, i. e. 24 minutes, therelay T3 is energized mthe following circuit: earth, contact 5802, wiper62, contact 124, wiper 125, contact 149, lead 150, contact 147, relayT3, battery, earth. The relay T3 operates, opens its contact 156 andconnects the buzzer tone at its contact 151 to the windings II of therelays A2 and B2. The calling subscriber therefore immediately receivesthe buzzer tone. In addition however the contacts 69 and 79t3 are alsoopened and the contact 152162V is closed, hence the speaking connectionis interrupted. Nevertheless, however, the relay B2 is maintainedenergized over the contactI 152753 and the resistance 68. v

If a connection has been set up to the traiic zone V, then the wiper 62of the digit switch MS2 stands on the contact 153, so that the wiper 154is connected up. The normal contact 155 of this switch is connected withlirst time unit moved on to the contact 157,

which is connected with the contact 158 of 'ZS2.`y At the end of thesecond time unit the driving magnet D6 of ZS1 again receives an impulseand the wiper 154 reaches the contact 159, which is connected with thecontact 160 of ZS2. The relay T3 is then at once energized and bringsabout the circuit changes already described.

When the calling subscriber hangs up his receiver at the end of aconversation in one of the trailic zones II to V, the relay A2 isenergized as already -described and transmits a metering impulse overthe lead 41 to the metering repeat relay ZR 'in Fig. 1. Thereby therelay HR is again energized, and by closing the contact 105 connects thedriving magnet D, of ZS2 to the impulse contact 51a2. The relay HR atits contact The wiper- 106w' short circuits the relay A2, so that the irelay A2 slowly releases and opens the contact 51a2 in the circuit ofthe magnet D4 and also the contact 100a2 in the circuit of relays HR andZR.

The-magnet D2 releases and after a little while the slow acting relay HRalso releases. Thereupon the relay A2 again operates and causes thetransmission of a second metering impulse and the moving on of theswitch ZS2. This cycle is repeated until the wiper 77 reaches a contact,over which the relay B2 is short circuited. If the zone switch ZS1 wasmoved on three times during a conversation in the second traiiic zone,the wiper 125 stands on the contact 161, which is connected with thecontact 162 of the switch ZS2. When the wiper 77 reaches this contact,the relay B2 is short circuited, since earth is connected' to the wiper77 over the contact 5802 wiper 62, contact 124, wiper 125, contacts 161and 162. The relay B2 releases, opens contacts 93 and 10452, whereby therelays C2 and S1 are permanently de-energized.

As soon as the transmission of metering impulses commences, the Contact127282 was opened, this contact being closed only in the first positionof the switch ZS2, that is when the wiper 77 stands on the contact 92.Thus the operation of the time switch Ze is'prevente'd during meterimpulse transmission.

The switches MS2, ZS1v and Ze are moved on into their normal positionwhen the relay C2 is de-energized after the release of relays B2 and S,.The moving on of the time switch Ze is effected by the alternateoperation of the driving magnet D5 and the relay U2. The circuit of thedriving magnet D5 of the time switch Ze is closed over: earth, battery,magnet D5, contact 1281112, off normal contact 170eze, relay HR, windingII, earth. The magnet D5 closes its contact 1715 and thereby energizesthe relay U2, which opens the contact 12811-2, so that D5 isde-energized. The relay U2 is now deenergized and again closes itscontact 128%2, so that the magnet D5 receives another impulse. Thecontact 170eee is opened when the time switch Ze reaches its normalposition. The circuit for driving magnet D6 of the zone switch ZS1 isclosed over: earth, battery, magnet D5, contacts 172ezs 117u2 winding IIof relay HR, earth. The magnet D, energizes the relay U2 over itscontact 173d6. The contact 17 2762s, is opened when the zone switch ZS1reaches its normal position and the magnet D6 cannot again be energized.The circuits for the magnets D2 and D2, which move the digit switch MS2and the zone switch ZS2 respectively into the normal position, havealready been previously described.

The trunk line VI1 cannot be taken into llO use so long as any of theswitches MS2, ZS1 or ZS2 remain in the operated condition. This 1s dueto the relay HR which at its contact'l46 closes a circuit for the relayS at the repeater Ue (Fig. l). As already mentioned, the relay S isenergized over the oft' normal Contact 10T/ums1 during the releasingmotion of the digit switch MSI. )Vlien the digit switch MS1 reaches itsnormal position, the contact 107 kms, is opened and the contact 1751ns1is closed. It at this time the relay HR in Fig. 3 is still energized,the relay S is maintained energized as follows: earth, resistance 176,contacts 146h1', 4202, lead 41, contact 17 lvmsl, relay S, battery,earth. The relay S therefore maintains its contact 18s open, so that itis impossible for the trunk line .VI1 to be taken into use by a testingsecond preselector II.V)V,.

If a call is set up between the subscriber Tn3 of the main exchange HA,(Fig. 4) and a subscriber o't' an exchange accessible over the trunkline VLS, the relays C6, AG and BB, are energized after the preselectingdevices IVW 2 (Fig. 4) and II.Vl/V2 have been positioned. Thereafter inlinown manner the first numerical switch I GrlV2 is set on a level towhich the trunk line VL., is connected. When such a free trunk line hasbeen found, the following circuit is established: earth, windings I andII of relay P3, contact 206%, wiper 207, contacts 205 and 208%, relayC7, lead 209 of the trunk line VL9, junction point 202, lead 210 of thetrunk line VL6 to battery over switching devices of the selectors in thedistant exchange. The relay C, closes the contact 21107 located inparallel with the contact 208@8 and energizes the relay VS over thecontact 2120 the contact 213 of the digit switch MS3 and the wiper 214.Relay V,3 opens the contact 208/08 and at contact 215e8 connects therelay A7 to battery over the resistance 216. Between the trunk lines VL8and VL9 lie the switching members of the meter operating devices,comprising the switching devices MS3, ZSI and ZS2. The method ofoperating these meter operating devices corresponds to that shown inFig. 2, so that it is unnecessary to describe the circuit changes. Therelay B7 corresponds to the relay B2 and the relay T4 corresponds to therelay T3.

It can be seen from Fig. 3 that all the meter operating devices areconcentrated in the main exchange HA. The value ot the connection isdetermined by the location of the calling and wanted exchanges. Now Fig.5 shows the position of the exchanges in a telephone area. HA is againthe main exchange, to which are connected the subexchanges UAI-UAVI.Calls between subscribers connected to different sub-exchanges arealways set up over the main exchange. Nevertheless the charge made isbased only on the distance between the two sub-exchanges for instancebetween the exchanges UAI and UAII. From the exchange UAI the othersub-exchanges lie in the following traiiic zones: UAII in the zone II,exchanges UMH and UAVI in the zone III, UAV and UAV in the Zone IV. Fromthe exchange UAII however, the exchanges UAI and UAIII lie in the zoneII, exchange UAIV in the zone III and UAV and UAVI in the zone IV.Although the digit switches, for instance, for a call to thesub-exchange UAIV, must always be set on the same contact, the meteroperating devices in the main exchange must be operated in a differentmanner according to whether a call originates in the exchange UAI or inthe exchange UAH. It would therefore be necessarv to provide specialmeter operating devices for each sub-exchange. This defect Vis howeveravoided by inserting auxiliary devices between the individual switchingmembers of the meter operating devices, these auxiliary devices servingto make the meter operating devices suitable for the incoming trafiicdirection, because this direction determines the location of the callingexchange. The lines leading from the contacts of the digit switches MS2(or MSB) to the wipers of the zone switch ZS1 (or ZS() are taken overthe distribution strips VLe, as can be seen from Figs. 6 and 7. Thesedistribution strips are also shown in Fig. 2 by thick lines, but werenot taken into consideration when describing the circuit changes.

Now Fig. 6 shows the connection between the auxiliary digit switch MS2and the zone switch ZS1 of the meter operating devices, which areassociated with the sub-exchange UAI. Now the sub-exchange UAII, havingthe calling number 81, lies in the second zone of the sub-exchange UAI;hence the wiper 125 of the zone switch ZS1 is connected with the Contact124 of the auxiliary digit switch MS2, this being effected over the00ntacts 400 and 401 by the distribution strlp 300. The traiiic zone IIIcontains the sub-exchanges UAIII and UAVI, having the call numbers 82and 85, hence the contacts 224 and 225 are connected over the contacts402, 403, 404 and the distribution strips 301 and 302 to the wiper 143of the zone switch ZS1. The contacts 226 and 227 of the auxiliary digitswitch MS2 onto which the wiper 62 is set for connections in thesubexchange UAV and UAVI, are connected with the wiper 146 of the zoneswitch ZSI over the contacts 405, 406 and 407 and the distributionstrips 303 and 304.

F ig. 7 shows the connection of the auxiliary digit switch MS2 with thezone switch ZS, for the meter operating devices associated with thesub-exchange UAII. The contact 224 of MS2, upon which the wiper 62 isset for calls to the sub-exchange UAIII,

is likewise connected with the contact 403;

1. In a measured service telephone system,

a main exchange, a plurality of sub-exchanges, trunking facilltiesenabling the establishment of talkin connections -between lines of anytwo su -exchanges -via said main exchange, meters for the calling lines,and means at the main exchange for operating the meter of a calling lineat the termination of a call a number of times dependent on the durationof the call.

2. In a measured service telephone system, a main exchange, a pluralityof sub-exchan es, trunking facilities enabling the establis ment oftalking connections between lines of any Vtwo sub-exchanges via saidmain exchange, meters for the calling lines, and means at the mainexchange for operating the meter of a calling line a number of timesdependent on the value of the connection and the duration of the call,the said meter operating means being rendered eective only after thereceiver has been replaced on its switch-hook.

3. In a measured service telephone system, comprisin a main exchange anda plurality ,ot sub-exc anges, meter controlling devices at the mainexchange, means for causing one of said devices to prepare a meteroperating circuit `incidental to the process of setting upa connectionbetween lines of two sub-exchanges, said device rendered effective atthe termination of the call'to operate a metera number of timesdependent on the duration of the talking connection.

4. In a measured service telephone system, a main exchange, a pluralityof sub-exchanges, subscribers lines terminating in said exchanges,meters for said lines, trunk lines common to all the subscribers lines,numerical switches individual to the sub-- scribers lines of thesub-exchanges and hav ing access to said trunk lines, other numericalswitches individual tothe lines of the main exchange, meter controlapparatus for operating the meters of the sub-exchange lines located infront of the associated numerical switches, and other similar metercontrol apparatus in the main exchange for operating the meters of thelines in the main exchange located beyond the associated numericalswitch.

5. In a measured service telephone system, a calling line in oneexchange, a called line in a second exchange, electro-mechanical meansfor establishing a talking connection between said lines, a meter forthe calling line, means responsive to the settin up of a connection fordetermining themmimum number of times the meter of the calling line willbe operated if the called subscriber responds,.and means automaticallyoperated periodically during the time the connection is maintained tore-determine the minimum number of times the meter will be operated.

6. In a measured service telephone system, a calling line in oneexchange, a called line `in a second exchange, electro-mechanical meansfor establishing a talking connection between said lines, a meter forthe calling line, means responsive to the setting up of a connection fordetermining the minimum number of 'times the meter of the calling linewill be operated if the called subscriber responds, and means responsiveto the replacement of the receiver at the calling line `for causing theoperation of the meter as last predetermined.

7 In a measured service telephone system, three exchanges, a calling anda called line in the first and third respective exchanges connected viathe second exchange, a meter for the calling line, meter controlequipment located exclusively at the second exchange, means for settingsaid equipment to cause the meter to be operated a detinite number oftimes if the established call is terminated within a predeterminedperiod, and auxiliary means periodically effective after the lapse ofsuch period for changing the meter control equipment to causev the sameto operate the meter a greater number of times following the terminationof the call.

8. In a zone metering telephone system, a. directively controlled metercontrol switch operated during the setting up of a connection to selecta bank contact individual to the particular zonel called, a timecontrolled automatic switch, conductors of said zone selecting switchextending via wipers of said time controlled switch and a distributingframe intermediate to said switches so that the diierent switches of thediiierent calling sub-exchanges may be each operated in the same mannerto prepare charging circuits of different values when connections areset up to the same called sub-exchange.

9. In a measured service telephone system, a calling and a called line,means including an impulse repeating relay and automatic switchescontrolled thereby to establish a talking connection between said lines,a meter for the calling line, and means for causing said impulsing relayto automatically repeat impulses to said meter.

10. In a measured service telephone system, a calling and a called line,means including an impulse repeating relay and automatic switchescontrolled thereby to establlO Alish a talking connection between saidlines,

a meter for'the calling line, and means for causing said impulsing relayto automatically repeat impulses to said meter, the number of impulsesrepeated to said meter depending on the duration of the call and thevalue of the connection.

1,1. In -a measured service telephone system, a meter control switch,directively con trolled automatic switches for' use in setting uptalking connections between subscribers lines, said meter control switchalso o erative responsive to one or more series o impulses transmittedto said automatic switches to Eredetermine the charge or rate of chargeto e made for a connection, and means for causing said meter controlswitch to automatically o erate a predetermined distance to render t esame again under control of each of the impulses of the succeedingseries transmitted to one of said automatic switches to determine thelapse time rate of charge to be made for the connection.

Signed by me at Berlin, Germany, this

